Biometric authentication systems are used for authenticating and/or verifying users of devices incorporating the authentication systems. Biometric sensing technology provides a reliable, non-intrusive way to verify individual identity for recognition purposes.
Fingerprints, like various other biometric characteristics, are based on distinctive personal characteristics and are thus a reliable mechanism for recognizing an individual. There are many potential applications for using fingerprint sensors. For example, fingerprint sensors may be used to provide access control in stationary applications, such as security checkpoints. Electronic fingerprint sensors may also be used to provide access control in mobile devices, such as cell phones, wearable smart devices (e.g., smart watches and activity trackers), tablet computers, personal data assistants (PDAs), navigation devices, and portable gaming devices.
Fingerprint sensors are often incorporated into consumer devices, such as mobile devices. In some cases, the fingerprint sensor is integrated with a “home” button on a cell phone. The home button is commonly a mechanical button. A user can apply force to the home button to press or click on the home button to actuate various features of the cell phone, such as returning to a home screen. In situations where a fingerprint sensor is integrated with the home button, the user can “touch” (as opposed to a press or click) on the home button to perform fingerprint authentication, for example, in response to a request from the cell phone operating system or an application running on the cell phone.
Increasingly, however, the trend in mobile devices is to eliminate the home button or eliminate a mechanical switch from the home button to lower cost and/or thickness.